I am using the Mitsubishi 60-A; which I guess is what came with the 20B.

I put on a larger size pulley to reduce the rpm.

It has in internal voltage regulator, which is powered, and provides field current, directly from the output via an internal connection. 

I use the internal regulator, but made the relatively easy mod of disconnecting the internal connection from the output so I can provide that from an external circuit.  In that circuit I have the ‘crowbar’ over-voltage protection (bought from Aeroelectric Connection). It connects across the circuit breaker; and in the event of over voltage (I think at 16-16.5v) it shorts to ground and trips the breaker.

Initially I found that the charging voltage was on the high side; sometimes up to 15v. I realized that the regulator was then reading the voltage from my external supply; which after traveling to the battery and through my circuit (battery in front, engine in back) had some drop; thus causing it to charge to a higher voltage. Solved that by using the external circuit to power a relay close to the alternator which powers the regulator from the output.  All is well.  Dave Leonard has the same setup; and same story.

Al

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of josrph berki
Sent: Tuesday, September 21, 2010 3:14 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Alternator

Ed,

Thanks for the input.  Did you modify it at all to remove the regulator or

provide for disabling the field?

Joe

----- Original Message -----

From: "Ed Anderson" <eanderson@carolina.rr.com>

To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>

Sent: Tuesday, September 21, 2010 6:38 PM

Subject: [FlyRotary] Re: Alternator

> Joe, I still fly with the old standard Rx-7 alternator - have been ever

> since I launched in 1998 - never failed so I'm still hauling around about

5

> lbs more weight that I need to.  So can't offer you any light weight

> solutions.  But, there are others that have done research on light weight

> alternators whom I'm certain will offer suggestions.

>

> Ed

>

> Edward L. Anderson

> Anderson Electronic Enterprises LLC

> 305 Reefton Road

> Weddington, NC 28104

> http://www.andersonee.com

> http://www.eicommander.com

>

>

> --------------------------------------------------

> From: "josrph berki" <jskmberki@windstream.net>

> Sent: Tuesday, September 21, 2010 6:21 PM

> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>

> Subject: [FlyRotary] Alternator

>

> > What alternator is being used on the rotary?  With EFI and electronic

> > ignition I would think a 60 amp would be suitable.  Does anyone have a

> > light

> > weight small solution?  Thanks for any help.

> >

> > Joe Berki

> > Limo EZ

> >

> >

> > --

> > Homepage:  http://www.flyrotary.com/

> > Archive and UnSub:

> > http://mail.lancaironline.net:81/lists/flyrotary/List.html

>

>

> --

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